Agent: `opencode-task77-slice-a-20260222T000100Z-j4p2`

alias: opencode-task77-slice-a
mission: Implement TASK-77 slice A parser-selection-stage module + focused tests without touching tokenizer.ts
status: done
branch: main
started_at: 2026-02-22T00:01:00Z
heartbeat_minutes: 5

Current Work (newest first)

[2026-02-22T00:01:00Z] intent: extract pure parse-result selection logic from src/core/services/tokenizer.ts into new stage module and add focused tests for selection behavior.
[2026-02-22T00:01:00Z] plan: write failing tests first in src/core/services/tokenizer/parser-selection-stage.test.ts, then add module src/core/services/tokenizer/parser-selection-stage.ts, then run targeted test command.
[2026-02-22T00:03:30Z] complete: added pure parser selection stage module + helper exports and focused tests for scanning preference, mecab fallback split, and suspicious-kana tie-break; verified with bun test src/core/services/tokenizer/parser-selection-stage.test.ts (3 pass, 0 fail).

TASK-77 already exists in Backlog (task_search hit confirmed).
Slice A should preserve existing behavior from tokenizer parse candidate selection path only.